The invention relates to improvements in shoulder rests for violins and analogous stringed musical instruments. More particularly, the invention relates to improvements in shoulder rests of the type disclosed in commonly owned German Pat. No. 26 04 897 (published Aug. 19, 1976 and granted Jun. 22, 1978), in commonly owned German Auslegeschrift No. 26 59 869 (published Aug. 18, 1977), in commonly owned German Pat. No. 30 33 310 (published Apr. 8, 1982 and granted Jun. 16, 1982) and in corresponding commonly owned U.S. Pat. No. 4,386,548 (granted Jun. 7, 1983).
The above enumerated commonly owned prior publications disclose shoulder supports wherein a first clamping device is movable toward and away from a second clamping device against the resistance of a self-locking sleeve which maintains the two clamping devices at a selected distance from each other. Reference may be had, for example, to the drawing of German Pat. No. 26 04 897 which shows a self-locking sleeve. The clamping devices can engage selected portions of the body of a stringed musical instrument and are mounted on a carrier which further supports a shoulder-engaging member, e.g., a pad or a cushion. The clamping devices are adjustable to change the distance of the respective portions of the carrier from the body of the musical instrument Such multiple adjustability enables the player to select an optimal position of the pad or cushion relative to the body of the musical instrument. Moreover, the shoulder rest can be affixed to instrument bodies having different sizes and/or shapes. Still further, the shoulder rest can be adjusted to fit the stature of the player, particularly the vertical distance of the clavicle from the chin.
A drawback of presently known shoulder rests is that the mutual spacing of the clamping devices cannot be fixed with a desired degree of reliability. Thus, if the stress upon the adjustable clamping device reaches a certain value, the self-locking sleeve yields and permits a shifting of the movable clamping device toward or away from the other clamping device This can affect the comfort and the quality of play of the person using the musical instrument. Aging of the self-locking sleeve is one of the primary reasons that the useful life of such sleeves is rather limited and that their self-locking action deteriorates with time.
Certain additional conventional shoulder rests are disclosed in U.S. Pat. No. 2,747,452 (granted May 29, 1956) to Goldberger and in commonly owned U.S. Pat. No. 3,479,916 (granted Nov. 25, 1969).